The BBC's new fantasy drama Atlantis has been recommissioned for a second series, it was announced today - after just four episodes of the first run.

Created by Howard Overman, Johnny Capps, and Julian Murphy - part of the team behind Merlin, whose gap it is filling - the first episode, which aired on BBC One on Saturday 28th September, drew an audience of 8.4 million viewers (including catch-up over seven days), making it the biggest new Saturday-night drama series launch in the UK since Robin Hood in 2006, and also up on the launch of Merlin in 2008. Across the first three episodes, the show - made by Urban Myth Films - has averaged a consolidated audience of 6.7 million, and is averaging 7.4 million viewers in Live+7.

BBC One controller Charlotte Moore said:

Atlantis delivers original British drama with the kind of scale and ambition that we've come to expect from the cinema. It feels very much at home on Saturday nights on BBC One. It's been wonderful to watch Howard and the team create a whole new world, brilliantly inspired by Greek mythology, which is proving a hit with all the family, and a second series is richly deserved.

Ben Stephenson, the controller of BBC Commissioning, commented:

Atlantis has quickly made its mark and established itself as the new weekly fantasy drama fix for all the family on BBC One. The show is packed with creative ambition which is a credit to the team involved, and a second series will ensure the show builds and grows with the audience.

In a joint statement, Capps, Murphy, and Overman said:

We are all thrilled at Urban Myth Films that Atlantis has been recommissioned and look forward to continuing the legend next year.

The 13-part series follows the adventures of Jason (Jack Donnelly), Hercules (Mark Addy), and Pythagoras (Robert Emms), who battle against some of the most famous names of Greek legend, often in unexpected guises. The show also stars Jemima Rooper (Medusa), Aiysha Hart (Ariadne), Sarah Parish (Pasiphae), and Juliet Stevenson (The Oracle). All of these characters will return in series two. The number of episodes of the second series is yet to be confirmed, though.

Previously unannounced guests still to come include Robert Lindsay and John Hannah, who have forthcoming roles in the current series, which continues on BBC One until late December.